Vunipola, who was named in the party alongside fellow uncapped front-rower Tom Youngs, has excelled in the Aviva Premiership this term. He was awarded Man of the Match in Saracens' first two matches of the season and has profited from Alex Corbisiero's misfortune with the London Irish prop currently sidelined due to injury.

The Sarries prop will now look to break into the first XV for their match with Fiji on November 10 with Joe Marler seemingly in charge of the loose-head berth after starting all three of their Tests in South Africa back in June. Vunipola will work closely with scrum and forwards coach Graham Rowntree and the former Test prop revealed that he has been keeping a close eye on Vunipola's development.

"We've been watching this young man for some time," Rowntree told reporters at the unveiling of the squad. "He's played throughout our age-grade system. Alex Sanderson, the forwards coach at Saracens, coached him at the England Under-18s four years ago.

"He played two years with the England U20s and he's got himself fit, very fit. His game has just come on, I've watched him very closely. I'm looking for a fault in his game and I can't find one at the moment. His form has been exceptional within the Premiership so he was delighted and I'm looking forward to working with him."

Vunipola will now be under England coach Andy Farrell's watchful eye and he is familiar with the prop having coached him at Saracens. "He's an exceptional prop forward with ball in hand," Farrell said of Vunipola. "His form this year, as Graham alluded to, has put down to a change of attitude. He's grown up a lot over the last six months. He's really got stuck into his living outside of rugby, his fitness and his training is second to none. He's a guy that loves playing rugby and he's excited about the challenge ahead."

And former England skipper Lewis Moody has said that Vunipola's call-up epitomises the ethos of the current regime with the focus already on the 2015 World Cup.

"I think his inclusion is a fast-track by every standard," Moody told Sky Sports News. "I don't think he would have been in had Corbisiero been fit. But it's a good opportunity - Stuart has always spoken about bringing young guys in and the tendency towards youth is the trend.

"But you always have to have that balance alongside some guys with experience. You look at the teams that have won the World Cup and generally they have around 600 caps and that's something that Stuart Lancaster has always looked at. If this England team is looking to get that sort of experience then Stuart has said that he wants to stick with a group of players and show them loyalty through to 2015."